Radiation therapy for cancer uses ionizing radiation to kill cancer cells and shrink tumors in the body. This type of treatment focuses on the area of cancer and approximately half of all patients diagnosed with a cancer are treated with radiation therapy, whether alone or in conjunction with other types of cancer treatments.
What Are the Different Types of Radiation Treatments?
Different types of radiations are used to treat different types and stages of cancer and treatment and dosage varies from patient to patient. External radiation is a beam-like procedure in which the radiation comes from a machine that the patient is placed inside. Internal radiation is a newer and more pinpointed procedure in which the radiation is implanted in or near the tumor to give it the highest amount of radiation possible, with very little exposure or damage to surrounding tissues. This procedure is called internal or interstitial brachytherapy.
Interstitial brachytherapy uses radioactive material placed directly into or near a tumor to kill malignant cells. In anatomy, interstitial indicates the area between the cells of a structure or part. Placing the radiation treatment directly in contact with or as close to the growth as possible, is less invasive than other procedures. It also allows a lower dose to be used and reduces damage to surrounding healthy cells and tissue.
How Brachytherapy Works
Brachytherapy is a form of radiotherapy in which the source of irradiation is placed close to the tumor or inside a body cavity. In interstitial brachytherapy, the radioactive source is delivered directly inside the tumour by hollow needles, seeds or wires and may be used alone or with external beam radiation. The radioactive source may be permanently implanted, removed after the required dose or repeated as necessary. The most common types of cancer indicated for this treatment include early stage prostate cancer and penile cancer. Radiation oncologists also use several types of brachytherapy for the treatment of cervical, endometrial and bile duct cancers as well as soft tissue sarcomas. It is less commonly used to treat breast cancer and cancers of the head, neck, lung and esophagus.
Benefits of Interstitial Brachytherapy
Benefits include that interstitial brachytherapy allows a larger, focused dose which increases the likelihood of destroying the tumour in a less invasive way. For example, in treatment of the prostate, only the organ and a small margin around it is affected, similar to the area that would be removed by a surgeon in a more invasive prostatectomy. Interstitial brachytherapy also has a therapeutic advantage over general external radiation which damages other cells in a greater area. It is becoming the best choice of treatment for aggressive organ-confined prostate cancer (that has not spread to other parts of the body). In most cases the patient is able to avoid radical treatment such as surgery and chemotherapy.
Newer methods to implant the radiation sources has improved brachytherapy and focus the treatment where it is needed and made it a good choice for localized therapy. Other types of cancer are also being treated with this method; a recent study demonstrated that patients with ocular melanoma (cancer in the eye) treated with interstitial brachytherapy, avoided the removal of the eye.
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Noreen Kassem - Noreen Kassem is a hospital doctor based in London, UK. She has extensive experience in clinical research and an undergraduate honors ...
